Nonlinear heat transfer processes in a two-phase thermofluidic oscillator

► We develop a nonlinear model for a two-phase heat-powered thermofluidic engine. ► We compare the results with an existing linear model and experimental observations. ► The two models predict a similar oscillation frequency for the fluid pumping device. ► The predicted efficiencies are dissimilar and in some cases have different trends. ► The nonlinear model gives more realistic predictions of actual engine performance.